Continuous solvent extraction apparatus



Jan. 25, 1966 FERRARl 3,231,090

CONTINUOUS SOLVENT EXTRACTION APPARATUS Filed May 17, 1961 26 FIG. I M

INVENTOR. A m/re: f'rrarz United States Patent Office 333L030 Patented Jan. 25, 1956 3,231,090 CONTINUOUS SOLVENT EXTRACTION APPARATUS Andrs Ferrari, Scarsdale, N.Y., assignor to Technicon Instruments Corporation, Chauncey, N.Y., a corporation of New York Filed May 17, 1961, Ser. No. 117,766

4 Claims. (Cl. 210-151) This invention relates to the separation of immiscible liquids of different specific lgravities, respectively, from each other and, more particularly, to an apparatus for continuous solvent extraction and separation.

One of the objects of the present invention is to provide an apparatus for continuously separating immiscible liquids of different specific gravities, respectively, from each other during their flow as a mixture in a stream.

Another object is to provide apparatus which is especially useful in connection with solvent extraction techniques whereby the apparatus permits selective continuous extraction, separation and collection of either the heavy phase or the light phase of the liquid mixture.

Another object is to provide a solvent extractor especially useful for continuous solvent extraction and which is provided with means for mixing the constituent liquids of the sample stream.

The above and other objects, features and advantages of the invention will be more fully understood from the following description of the presently preferred embodiments of the invention considered in connection with the accompanying illustrative drawings.

In the drawings:

FIG. 1 is 'a more or less diagrammatic view illustrating the apparatus of the invention, with the solvent extractor shown on an enlarged scale; and

FIG. 2 is a viewsimilar to FIG. 1 illustrating a modification of the invention.

Referring now to the drawings in detail and particularly to FIG. 1, the apparatus comprises a pump 12 and the solvent extractor 14 of the present invention according to the presently preferred embodiment of the invention. Pump 12 is preferably of the positive displacement, peristaltic tube type shown in U.S. Patent No. 2,935,028 and issued May 3, 1960, and comprises a series of resiliently flexible pump tubes 16, 17, 18 and 20 which are compressed along their lengths against a platen 22 by a series of pressure rollers 24 which are'r'noved by sprocket chains 26 longitudinally of the pump tubes, The collapsing of the pump tubes by the longitudinally moving pressure rollers causes the liquid in the pump tubesto flow in the direct-ion of movementof the pressure rollers for the pumping operation and various rates of flow of the liquids can be obtained by varying the internal diameter of the respective pump tubes..

The sample liquid is supplied to pump tube 16, the extracting solvent is supplied to pump tube 18, and air or other inert gas is supplied to pump tube 17. The different fluids are transmitted through their respective pump tubes by the action of the pump to a fitting 27 where they join each other to form a segmented stream comprising a series of liquid segments, each containing a portion of the sample and a portion of the solvent, separated from each other by a series of intervening air segments. The segmented stream is transmitted by the action of pump 12 through conduit 28 to the solvent extractor 14 whose tubular inlet end 30 is provided with a mixing device 32 which thoroughly mixes the different constituent liquids of each liquid segment together. In the use of the apparatus for solvent extraction purposes, this mixing operation is extremely important because good extraction can only be obtained when the extracting solvent is thoroughly mixed with the liquid undergoing extraction. It is within treating the lighter liquid in a continuous manner.

the scope of the invention to supply directly to the solvent extractor 14 through conduit 28, a stream containing a mixture of immiscible liquids of different specific grav-ities, for example, a mixure of the liquid which is to undergo extraction and the extracting solvent. In the solvent extractor, the liquids are separated from each other and either the lighter or the heavier liquid can be collected, processed or treated for analysis.

The solvent extractor 14 is of tubular construction and is preferably made in one piece of glass. The extractor comprises a vertical chamber 33 with the inlet tube 30 at its upper end, an outlet tube 36 at its lower end, another outlet tube 38 above the lower outlet 36 and below the inlet 30, and a vertical overflow tube 40 which is open at its opposite ends and is connected to chamber 33 by a horizontal tube 42 which is slightly above tube 38. The open upper end of tube 40 provides a vent for the chamber and the air segments of the segmented stream are vented to the atmosphere. The lower open end of tube 40 provides an outlet for excess liquid from the chamber. The inlet tube 30 is connected to conduit 28 and the outlet tube 36 is connected to a conduit 44 which is connected to pump tube 20. Outlet tube 38 is provided with a tube 46 which is closed by a manually operable pinch clamp 48 or in any other suitable way.

The mixing device 32 is disposed in chamber 33 and comprises a series of spherical members 50 spaced from each other in the direction of flow of the incoming stream and connected in fluid-flow communication with each other by a series of intervening tubular connecting parts 52 which have cross sectional areas that are less than the cross sectional areas of the spherical parts. This causes the rate of flow of the incoming stream to vary as it passesthrough successive members 50 and 52 resulting in turbulence and mixing of the liquids in the stream. The outlet end 54 of the mixing device is positioned above outlet at and below outlet 38.

' As the incoming stream flows into chamber 33, the heavier phase of the mixture tends to settle toward the bottom of the vertical chamber and the lighter phase of the mixture tends to rise above the heavier phase. If itis desired to collect the heavier phase of the liquid, outlet 38 is closed by pinch clamp 48 and the internal diameter of pump tube 20 is selected so that the rate of flow of the separated heavier liquid through outlet 36 is less than the rate of flow of the heavier liquid portion of the incoming mixture through inlet 30. This causes all of the lighter liquid plus a small portion of the heavier liquid to overflow through tubes 42 and 40 and only the heavier liquid is transmitted from the chamber and flows through pump tube 20. If desired or if required, said heavier liquid can be concurrently treated for analysis by connecting the outlet end of pump tube 20 to a continuous analysis apparatus preferably of the type shown in US. Patent No. 2,797,149.

Referring now to FIG. 2, if it is desired to collect the lighter phase only of the mixture, pinch clamp 48 is released and outlet 38 is connected to a pump tube 54 by a conduit 56 so that liquid can be transmitted from the chamber through outlet 38 by the action of said pump tube. The internal diameter of pump tube 20 is selected so that the rate of flow of the separated heavier liquid through outlet 36 is greater than the rate of flow of the heavier liquid portion of the incoming mixture through inlet 30. This results in the flow of all of the heavier liquid plus a small portion of the lighter liquid through outlet 36 and the separated lighter liquid is pumped from the chamber through outlet 38 and conduit 56 by the action of pump tube 54. As indicated previously, the outlet end of pump tube 54 can be connected to an automatic analysis system for concurrently analyzing or Any excess liquid overflows through tubes 42 and 40, respectively.

In FIG. 2 it is to be noted that the mixing device 32 has been omitted from the chamber of the solvent extractor 14 and instead a horizontal helical mixing coil 58 has been provided in conduit 28 for mixing the constituent liquids of the stream. It is within the scope of the invention to mix the streams by either devices or by any other suitable device. It is also Within the scope of the invention to provide conduit 56 with a pinch clamp so that by properly selecting the size of pump tube the apparatus of FIG. 2 can be used to collect the separated heavier or lighter phase of the liquid by opening the pinch clamp, in the case of collecting the lighter phase, or by closing the pinch clamp in the case of collecting the heavier phase. Also, it will be apparent that pumps other than the type shown can be used in the practice of the invention. Separate pumps can also be provided for pumping each stream of the fluids, if desired or if necessary.

While I have shown and described the preferred embodiments of my invention, it will be understood that the invention may be embodied otherwise than as herein specifically illustrated or described, and that certain changes in the form and arrangement of parts and in the specific manner of practicing the invention may be made without departing from the underlying idea or principles of this invention within the scope of the appended claims.

I claim:

1. Apparatus for continuously treating a liquid stream comprising:

a junction having three inlets and one outlet;

first means for positively displacing a continuous liquid sample stream into one of said junction inlets;

second means for positively displacing an inert gas into the second of said junction inlets;

third means for positively displacing a liquid solvent which is immiscible with and of a different specific gravity than said liquid sample into the third of said junction inlets;

a horizontal helical mixing coil having one end thereof fluid-flow coupled to said junction outlet;

a vertically extended settling chamber fluid-flow coupled to the other end of said mixing coil;

said settling chamber having a first uppermost outlet for the removal of said inert gas;

a second outlet at the bottom of said chamber for the removal of the heavier liquid phase,

a third outlet above said second outlet and below said first uppermost outlet for the removal of the lighter liquid phase, and

a fourth outlet between said first and third outlets for the removal of the remaining liquid;

the outlet of said mixing coil being in fluid flow communication with said settling chamber above said outlets;

fourth means for continuously positively withdrawing all of the heavier liquid phase and a small portion of the lighter liquid phase from said chamber through said second outlet;

fifth means for continuously positively withdrawing a portion of the lighter liquid phase through said third outlet at a volumetric rate of fiow which is less than the volumetric rate of flow at which the lighter liquid phase is delivered into said settling chamber;

said first and fourth outlets comprising a vertically extending conduit open at both ends and a horizontally extending conduit fluidly communicating the interior of said settling chamber above said third outlet and below said outlet of said mixing coil with the interior of said vertically extending conduit intermediate said open ends of said vertically extending conduit;

said first, second, third, fourth and fifth means comprising positive displacement pump means.

2. Apparatus for continuously treating a liquid stream comprising:

a junction having three inlets and one outlet;

first persitaltic tube pump means for positively displacing a continuous liquid sample stream into one of said junction inlets;

second peristaltic tube pump means for positively displacing an inert gas into the second of said junction inlets;

third peristaltic tube pump means for positively displacing a liquid solvent which is immiscible with and of a different specific gravity than said liquid sample into the third of said junction inlets;

a mixing conduit having an inlet fluid-flow coupled to said junction outlet, and having an outlet;

a vertically extended settling chamber fluid-10w coupled to said outlet of said mixing coil;

said settling chamber having a first uppermost outlet for the removal of the inert gas,

a second outlet at the bottom of said chamber for the removal of the heavier liquid phase,

a third outlet above said second outlet and below said first uppermost outlet for the removal of the lighter liquid phase,

and a fourth outlet between said first and third outlets for the removal of the remaining liquid;

fourth peristaltic tube pump means for continuously positively withdrawing all of the heavier liquid phase and a small portion of the lighter liquid phase from said chamber through said second outlet;

fifth peristaltic tube pump means for continuously positively withdrawing a portion of the lighter liquid phase from said chamber through said third outlet at a volumetric rate of flow which is less than the volumetric rate of flow at which the lighter liquid phase is delivered into said settling chamber;

said first and fourth outlets comprising a substantially horizontally extending conduit having one of its ends fluid-flow coupled to the interior of said settling chamber above said third outlet, and the other of its ends bifurcated into an upwardly extending conduit and into a downwardly extending conduit.

3. Apparatus for continuously treating a liquid stream comprising:

a junction having three inlets and one outlet;

first means for positively displacing a continuous liquid sample stream into one of said junction inlets;

second means for positively displacing an inert gas into the second of said junction inlets;

third means for positively displacing a liquid solvent which is immiscible with and of a different specific gravity than said liquid sample into the third of said junction inlets;

a vertically extended settling chamber having a first uppermost outlet for the removal of said inert a second outlet at the bottom of said chamber for the removal of the heavier liquid phase, and

a third outlet between said first and second outlets for the removal of the remaining liquid;

a vertically extending mixing conduit disposed within said settling chamber having an inlet fluid-flow coupled to said junction outlet, a plurality of intermediate sequential constrictions and dilations, and an outlet in fluid-flow communication with said settling chamber above said second outlet and below said third outlet;

fourth means for continuously positively withdrawing a portion less than the entirety of the heavier liquid phase from said chamber through said second outlet at a volumetric rate of flow which is less than the volumetric rate of flow at which the heavier liquid phase is delivered into said settling chamber;

said first and third outlets comprising a vertically extending conduit open at both ends and a horizontally extending conduit fluidly communicating the interior of said settling chamber above said second outsaid settling chamber; said first and third outlets comprising a substantially References Cited by the Examiner UNITED STATES PATENTS let and above said outlet of said mixing conduit with 554,598 2/ 1896 Gilmore 55-176 the interior of said vertically extended conduit inter- 5 597,258 1/ 1898 Bovee 55176 mediate said open ends of said vertically extended 812,831 2/1906 Davidson 210-539 conduit; 897,125 8/ 1908 McCabe et al 551'76 said first, second, third and fourth means comprising 1,170,558 2/ 1916 Honnenbruch 210-83 a positive displacement pump means. 2,025,883 12/1935 Mobley 210-519 X 4. Apparatus for continuously treating a liquid stream 2,047,229 7/1936 Samiran 210-519 X comprising: 2,203,267 6/ 1940 MacDonald 55-176 X a junction having three inlets and one outlet; 2,214,248 9/1940 Hawley 2105 19 first peristaltic tube pump means for positively dis- 2,288,333 8/1942 Vinson 210-84X placing a continuous liquid sample stream into one 2,296,739 9/1942 Ray 23270.5 X of said junction inlets; 2,381,760 8/ 1945 Latham 210-84 X second peristaltic tube pump means for positively dis- 2,405,158 8/ 1946 Mensing 23-2705 placing an inert gas into the second of said junction 2,474,006 6/ 1949 Maycock. inlets; 2,474,007 6/ 1949 Maycock. third peristaltic tube pump means for positively dis- 5 1/ 9 4 Ng placing a liquid solvent which is immiscible with and 2,631,269 6/ 1954 Bergstl'om of a different specific gravity than said liquid sam- 2,785,766 3/ 9 Murd ck 23-270.5 ple into the third of said junction inlets; 2,797,149 6/1957 Skeggs 55-175 X a vertically extended settling chamber having 2,808,933 10/1957 Mobley 210519 X a first uppermost outlet for the removal of the inert 2,829,032 4/ 1958 Barley at 25 2,879,141 3/1959 Skeggs 210-519 X a second outlet at the bottom of said chamber for the 2,899280 8/1959 White1}ead et removal of the heavier liquid phase, and 2,933,293 4/1960 Penal? 2594 a third outlet between said first and second outlets for 295,028 5/1960 F 103 9 the removal of the remaining q 2,982,414 5/1961 HlIShStClIl 210-519 X 2985 305 5/1961 Nock et al. 210-83 a mixing conduit having an inlet fluid-flow coupled to 2,986,279 5/1961 Henigman 210-83 X said JUHCUOH outlet, and an outlet in fluid-flow com- 3 098 7/1963 Sk 210 330 X unication with said settling chamber eggs m 3,101,674 8/ 1963 Weiskopf et al 103-9 X fourth peristaltic tube pump means for continuously positively withdrawing a portion less than the entire- FOREIGN A EN ty of the heavier liquid phase from said chamber through said second outlet at a volumetric rate of 1,255,730 6/1961 flow which is less than the volumetric rate of flow 691,355 5/1953 Great at which the heavier liquid phase is delivered into OTHER REFERENCES Auto Analyzer, Technicon Instruments Corporation,

horizontally extending conduit having one of its ends Chauncey, New York, copyright 1957, 16 pages. fluid-flow coupled to the interior of said settling chamber above said second outlet, and the other of its ends bifurcated into an upwardly extending conduit and into a downwardly extending conduit,

REUBEN FRIEDMAN, Primary Examiner.

ROBERT F. BURNETT, CHARLES SUKALO,

Examiners. 

4. APPARATUS FOR CONTINUOUSLY TREATING A LIQUID STREAM COMPRISING: A JUNCTION HAVING THREE INLETS AND ONE OUTLET; FIRST PERISTALTIC TUBE PUMP MEANS FOR POSITIVELY DISPLACING A CONTINUOUS LIQUID SAMPLE STREAM INTO ONE OF SAID JUNCTION INLETS; SECOND PERISTALTIC TUBE PUMP MEANS FOR POSITIVELY DISPLACING AN INERT GAS INTO THE SECOND OF SAID JUNCTION INLETS; THIRD PERISTALTIC TUBE PUMP MEANS FOR POSITIVELY DISPLACING A LIQUID SOLVENT WHICH IS IMMISCIBLE WITH AND OF A DIFFERENT SPECIFIC GRAVITY THAN SAID LIQUID SAMPLE INTO THE THIRD OF SAID JUNCTION INLETS; A VERTICALLY EXTENDED SETTLING CHAMBER HAVING A FIRST UPPERMOST OUTLET FOR THE REMOVAL OF THE INERT GAS; A SECOND OUTLET AT THE BOTTOM OF SAID CHAMBER FOR THE REMOVAL OF THE HEAVIER LIQUID PHASE, AND A THIRD OUTLET BETWEEN SAID FIRST AND SECOND OUTLETS FOR THE REMOVAL OF THE REMAINING LIQUID; 